I drive a lot on the freeway since I commute to work about 35 miles one way and Lexus manual states I'm supposed to get about 26mpg freeway and 19 city. I know how much mpg I get since I reset my Trip A odometer every time I fill up and put a full tank of gas. My mpg is about 20.8mpg. Example: If my odometer reads 370 miles and I filled up 17.8 gallons then I got about 20,8mpg. How can I improve my mpg when considering:
1) My tires psi is at the recommended about 34psi
2) I do not have my windows rolled down while driving over 40mph
3) I do not like the AC on so rarely have it blasted
4) Just checked my engine air filter which was surprisingly clean. I still changed it with K&N
5) I dont have my interior nor my trunk stuffed with bunch of items that will cause extra weight.
6) My average speed is about 74mpg on freeway. I do not go pedal to the metal and zig zag through the freeway nor the city.
So how can I improve my mpg close to the factory 26mpg freeway?

 

UPDATE: recently took a few trips and wanted to update this post that I got max of 24 mpg highway. Combined with city, I get about 20.8 so still on par with my below comment.

I drive a 2007 AWD and get about 28 highway and 21 city. I typically stick around 80 mph on the highway (closer to 55 mph the better so your highway speed is fine). I'm sure some others can chime in with suggestions on cleaning any items under the hood that may be impacting your mpg. The 20.8 seems about on par with what I get out of tank though (I do a lot of stop and go on the daily).

 

I wish I got 28mpg. I'm thinking of getting an used Prius to commute to work with

 

2007 GS350 RWD, I commute 30 miles to work with a mix of city traffic and some freeway (been doing this commute for 3 years in my GS). My average is about 22-24 depending on how spirited I drive. You can try to calculate your gas mileage old school way without the using the lexus gas counter, to make sure its not off. Just reset your trip when you fill up, drive to empty, fill up and divide the miles by the gallons filled.

 

2010 GS350 AWD
Daily commute ~70Km total (60% stop and go traffic in well planned Toronto highway and ingenuously signalled city roads, 40% nice and empty private toll highway and empty rural roads)
Depending on how much i want to contribute to global warming (based on my dislike of Canadian winter)
- 10.5L/100 (22.4MPG) - keeping it near 2000-2500 RPM
- 13.5L/100 (17.4 MPG) - Redline is where its at cuz that's where shifts should happen

On highway only and speeding at 20% over posted, i consistently average 8.5L/100 and 27.7MPG

 

21.8 as daily mixed driving in ECO

 

Mine just dropped from 23 to 18 in just 1 tank of gas.No idea why.

 

thats exactly what I do

 

damn with gas about $4/gal that is a steep drop

 

You can try adding a few extra PSI to tires for better fuel economy. For long road trips I add like 5psi. Also driving at 74MPH you're fighting greater wind resistance and expending more energy to maintain speed so slowing down a bit can get you better MPG. Also during the winter gas stations switch to winter blends of fuel which have slightly lower MPG as well.

 

I have a GS460.

With stock wheels on the highway I was getting 28mpg at 80 mph, city 18mpg. With my mix driving I averaged about 21 mpg.

I changed my wheels to the 2016 rx f sport 20 inch wheels. The rim alone is 35 pounds! Lol after putting them on I now average 24 mpg highway and 16 mpg city. With my mix driving 18 mpg.

I do drive aggressive though.

 

I have heard this and always was in agreement. However, the instant mileage gauge (idk how accurate it is) shows I am getting over 30 mpg when I am doing 90mph and between 70-80 it's under 30 mpg.

 

26mpg? I average about 23-24mpg (90% highway), cruising ~73mph.

 

Were you behind an 18 wheeler when getting that higher MPG? Because otherwise I don't see how that would work. But if it is true then awesome keep going lol

 

Nope, see it on multiple occasions. I live in Florida too, so all flat lol. I would take a video but going 90 mph and using my phone...not a fan haha. I will see if I can have a passenger do it or if the road is clear for miles do it myself.